[PATCH] D79279: Add overloaded versions of builtin mem* functions

[JF Bastien via Phabricator via cfe-commits]

jfb added a comment.

> My point is that this has nothing to do with the ordinary semantics of `_Atomic`.  You're basically just looking at the word "atomic" and saying that, hey, a minimum access size is sortof related to atomicity.
> 
> If you want this to be able to control the minimum access size, you should allow that to be passed in as an optional argument instead.

OK so it sounds like you're suggesting *two* versions of the overloaded builtins:

1. `__builtin_memcpy_overloaded` which overloads on `volatile`, `restrict`, `__unaligned`, and address spaces, but **not** on `_Atomic` qualifiers.
2. `__builtin_atomic_memcpy_overloaded` which overloads on `volatile` (but unsupported for now), `restrict`, and address spaces, but **not** on `_Atomic` qualifiers (because it's implicit), and **not** on `__unaligned` because that's a constraint. This takes an extra "element size" parameter, which we hope folks don't confuse with the size parameter (I'd expect a template or macro wrapper to hide that extra parameter when actually using the builtin).

Of course, that's two versions for each of `memcpy`, `memmove`, `memset`, and any other `*mem` that we decide to add to this list of overloadable functions.

Is that correct?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D79279/new/

https://reviews.llvm.org/D79279